In order to distribute air supplied from an air pump or the like into a plurality of pipes, for example, a configuration so as to open or close two discharge ports 104a and 104b by subjecting a movable valve 121 connected to a spring 108 and an electromagnetic device 120 such as a solenoid via a piston rod 126 to reciprocating motion by a biasing action of the spring 108 and a driving force of the electromagnetic device 120 has been considered as shown in FIG. 12. Namely, in FIG. 12, when an electric current is not fed to the electromagnetic device 120, the movable valve 121 is drawn toward the right side in FIG. 12 due to the biasing action of the spring 108 to close the discharge port 104a, and as a result, the air supplied from an air pump or the like and flowing into an air chamber 123 at the suction side passes through the discharge port 104b and is discharged into a discharge pipe 124b. On the other hand, when an electric current is fed to the electromagnetic device 120, the movable valve 121 is moved toward the left side in FIG. 12 due to the driving force of the electromagnetic device 120 resisting the biasing action of the spring 108 to close the discharge port 104b, and the air supplied from an air pump or the like passes through the discharge port 104a and is discharged into a discharge pipe 124a 
Further, as shown in FIGS. 13A and 13B and FIGS. 14A-14C, it has been considered that a piston rod 226 on which a plurality of movable valves 221a-221e are mounted apart from each other is inserted into a cylinder 225 provided with a suction portion 223 and a plurality of discharge portions 222a-222c, and by a reciprocating motion of this piston rod 226 in the cylinder 225 by means of a drive source 214, the suction portion 223 is communicated with any of the discharge portions 222a-222c via a space partitioned by the movable valves 221a-221e in the cylinder 225 FIGS. 13A and 13B represents the case of providing two discharge portions 222a and 222b and FIGS. 14A-14C represents the case of providing three discharge portions 222a-222c. In FIGS. 14A-14C, the suction portion 223 is connected to the cylinder 225 via a branching port 228a or 228b. In the state shown in FIG. 13A, air supplied from an air pump or the like and flowing into the suction portion 223 passes through the space at the left side of the movable valve 221a in the cylinder 225 and is discharged into the discharge portion 222a, and on the other hand, as shown in FIG. 13B, when the piston rod 226 is moved until the movable valve 221a is located at the left side of an opening 223a of the suction portion 223, the air passes through the space between the movable valve 221a and the movable valve 221b in the cylinder 225 and is discharged into the discharge portion 222b. In the state shown in FIG. 14A, the air supplied from an air pump or the like and flowing into the suction portion 223 passes through the branch port 228a and the space between the movable valve 221b and the movable valve 221c in the cylinder 225 and is discharged into the discharge portion 222a, and in FIG. 14A, when the piston rod 226 is moved toward the right direction, as shown in FIGS. 14B and 14C, the discharge portion communicating with the suction portion 223 is changed from the discharge portion 222a to the discharge portion 222b, further to the discharge portion 222c in order according to the positions of the movable valves 221a-221e, and the air supplied from an air pump or the like is discharged into any of the discharge portions 222a-222c communicating with the suction portion 223.
In the conventional configuration shown in FIG. 12, its structure is such that the movable valve 121 undergoes reciprocating motion by the electromagnetic device 120 and the spring 108, and the both of the two discharge ports 104a and 104b are closed by this one movable valve 121. Therefore, the movable valve 121 and the spring 108 biasing the movable valve 121 for closing any of the discharge ports (the discharge port 104a in FIG. 12) have to be disposed with a partition wall having the discharge port being provided between them, and the movable valve 121 and the spring 108, after having been formed separately, are to be assembled via the discharge port, which leads to a problem that the production becomes complicated. Further, since the spring 108 and the movable valve 121 have to be formed separately, cost reduction by integrally forming the both to decrease the number of parts and simplify production steps cannot be achieved.
Meanwhile, in the case of a structure where the movable valve 121 is provided on each of the discharge ports 104a and 104b, though it is possible to provide the spring 108 and the movable valve 121 together on one side of a partition wall, two drive sources such as expensive electromagnetic devices 120 are needed, which leads to a problem of increase in cost. Further, if the number of branches is increased, additional electromagnetic devices 120 are needed accordingly.
Further, in the structures shown in FIGS. 13A and 13B and FIGS. 14A-14C, since in the cylinder 225, a connecting position of the suction portion 223 with respect to connecting positions of the discharge portions 222 is limited, there may be a case where a flow path between the joint of the suction portion 223 or the discharge portion 222 with the outside flow path and the given connecting position in the cylinder 225 is needed, and this may result in increase of cost and increase of a size of the branched portion. In addition, if the number of branches is three or more, as shown in FIGS. 14A-14C, branch ports 228a and 228b are needed, and also in this case, there is a problem that cost increases and a size of the branched portion increases.
The presently disclosed embodiment was made in light of the above-mentioned situation, and the object of the presently disclosed embodiment is to provide a valve structure enabling opening and closing of discharge ports to be controlled by driving two or more valve bodies with one drive source, thus minimizing increase in cost and size resulting from increase in the number of branches.